DNA distortion accompanies transcriptional activation by the metal-responsive gene-regulatory protein MerR

Journal Article · Tue May 22 00:00:00 EDT 1990 · Biochemistry; (United States)

DOI:https://doi.org/10.1021/bi00472a001· OSTI ID:5317633

Frantz, B; O'Halloran, T V ^[1]

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1. Northwestern Univ., Evanston, IL (USA)

Transcriptional regulation of the bacterial mercuric ion resistance operon (mer) in response to nanomolar concentrations of mercuric ion is achieved by the allosterically modulated transcriptional activator protein MerR. The authors now show that mercuric ion modification of MerR activates transcription, facilitating the conversion of an RNA polymerase complex with the mer promoter from the closed conformation to the strand-separated, transcriptionally competent open complex. An Hg-MerR-induced structural alteration at the center of the promoter has been detected in the presence or absence of RNA polymerase by use of chemical nucleases sensitive to variations in DNA secondary structure. This hypersensitivity correlates directly with transcriptional activation, lending further support to a previous proposal that a protein-induced distortion in local DNA structure can be the key step in an allosterically modulated transcription activation mechanism.

• OSTI ID: 5317633
• Journal Information: Biochemistry; (United States), Vol. 29:20; ISSN 0006-2960
• Country of Publication: United States
• Language: English

Related Subjects

63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
DNA
CONFORMATIONAL CHANGES
GENE OPERONS
TRANSCRIPTION
MERCURY COMPOUNDS
BIOLOGICAL EFFECTS
CATIONS
CHEMICAL ACTIVATION
GENE REGULATION
NUCLEOPROTEINS
RNA POLYMERASES
CHARGED PARTICLES
ENZYMES
IONS
NUCLEIC ACIDS
NUCLEOTIDYLTRANSFERASES
ORGANIC COMPOUNDS
PHOSPHORUS-GROUP TRANSFERASES
POLYMERASES
PROTEINS
TRANSFERASES
560300* - Chemicals Metabolism & Toxicology